SILICONE AND RUBBER POLYMERS

Insulation and Sheath Compounds

Silicone is a synthetic rubber. It is obtained as a result of a series of complex reactions of silicon element. Since the polymer composition does not contain halogen, it does not give toxic gas and smoke when exposed to flame. The salient features of using silicone elastomers in cable insulation and sheath are listed below.

Excellent dielectric properties
• High heat resistance (-60 +300 oC: with suitable type of additive)
• Very good resistance to aging factors (UV rays, ozone, corona effect, chemicals, humid and hot weather conditions)
• Excellent fire resistance, non-toxic gas and low smoke density

Silicone rubber compounds exhibit halogen-free properties under fire conditions. When silicone rubbers are exposed to a flame, they form a ceramic layer on the conductor that has an insulating feature, and thus tension is prevented. Silicone rubber compounds are used in oil resistant cables.

Silicone cables are produced by extrusion processes and vulcanized with different technologies.
1.Hot air tunnel
2.Solted salt bath
3.Pressure steam (6 ~ 20 bar)

The most preferred method for vulcanization is the hot air tunnel. The tunnel temperature is 200 ~ 300 ° C. The length of the tunnel affects cable production.

The formula of the simple silicone compound is as follows.
1.Base silicone
2.Kuvars
3.Peroksit
4.Pigment